Chapter 5: Turning Latin Nouns into Adjectives

§39. The Latin suffix -OSUS (> E -ous, -ose)

Here, for the first time, we meet a Latin adjective-forming suffix that has a somewhat more precise meaning than “pertaining to” or “like a —–.” It is a very productive Latin morpheme, creating a considerable number of English derivatives and influencing many others. The suffix is -ōsus, which regularly meant “full of.” Latin adjectives in –osus appear in English in one of two forms, –ous or –ose.

A. In the following examples, arranged by declension number, the English derivatives in –ous still convey the meaning “full of”; a few Germanic counterparts are supplied:

1st fam-osus (famous), glori-osus (glorious), fabul-osus (fabulous)
2nd numer-osus (numerous), odi-osus (odious = “hateful”), taedi-osus (tedious = “tiresome,” “wearisome”)
3rd amor-osus (amorous), odor-osus (odorous = “smelly”), oner-osus (onerous = “burdensome”), gener-osus (generous), lumin-osus (luminous)
4th sinu-osus (sinuous), sensu-osus (sensuous); cf. sensualis > sensual
5th speci-osus (specious); cf. speci-alis > special

The immediate predecessor of the English suffix –ous was the Old French –os, –us (Modern French –eux, -euse). Because –ous became so common an adjective ending in English, it was attached to other Latin derivatives that had never been -osus words—words like aqueous (L aqueus), various (L varius), arduous (L arduus) and tenuous (L tenuis). You can find out a lot about suffixes like –ous from a good English dictionary, especially the Oxford English Dictionary. Just look up the morpheme under –ous.

B. The other type of –osus derivative appears in English as an adjective in –ose:

E verbose (< L verbosus < verbum) = “full of words
E jocose (< L jocosus < jocus) = “full of jokes”
E lachrymose or lacrimose (< L lacrimosus < lacrima) = “full of tears”[1]


  1. This word is traditionally spelled lachrymose, but Latin students may prefer the alternative and equally correct form, lacrimose, which is based on the original spelling of lacrimosus.


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Greek and Latin Roots: Part I - Latin Copyright © 2016 by Peter Smith (Estate) is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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